import turtle


def drawsnow(n, size):   # 绘制雪花曲线 n是阶数 size是长度
    if n == 0:
        turtle.fd(size)
    else:
        for angle in [0, 60, -120, 60]:
            turtle.left(angle)  # 画笔左转angle度
            drawsnow(n-1, size/3)


turtle.setup(800, 600)
turtle.penup()
turtle.goto(-250, 150)
turtle.pendown()
turtle.pensize(3)
for angle0 in [0, 120, 120]:
    turtle.right(angle0)
    drawsnow(4, 500)
turtle.done()
